The invention relates to a mudguard for vehicles in general, such as motor cars, lorries, trailers and the like.
In particular it relates to a hydro-expeller mudguard, i.e. a mudguard able to reduce water sprays and expel water drained from the wheel housing during travel of a vehicle.
In the remainder of this description reference will be made, for the sake of brevity, to the water and the phenomena which arise in. connection with the travel of vehicles on wet roads: this, however, must not be understood as limiting the invention, which may also be applied with regard to the travel of vehicles on dry ground, since situations similar to those produced by water exist in the case of dust.
As is known, a situation which has important consequences for road safety is that caused by the water sprays of motor cars and lorries especially when travelling on wet roads.
In order to eliminate or in any case to reduce the negative effects arising from the mass of nebulized water created by the wheels of the vehicles, several kinds of mudguard have been proposed.
In simplified terms it may be stated that the known mudguards may be divided into two main categories: those where trapping of the spray is obtained by means of special surfaces applied inside the mudguard and those where the effects of air currents circulating inside the wheel housing are used, if necessary in combination with the abovementioned surfaces.
Examples of mudguards of the first type are described in European patent applications No. 528410 or No. 626308, while examples of the second type may be found in the international patent applications PCT/IB95/00071 or PCT/EP91/00461.
Basically, in the first case the trapping action is due to the fact that the water raised by the tyres is retained by the internal surface of the mudguard as a result of its configuration which prevents, or in any case limits, rebounding of the droplets sprayed against it.
For this purpose the mudguard is provided with a cavity whose surface facing the tyre is perforated or formed as a grill or in any other equivalent manner, so as to slow down and deviate the droplets towards the inside of the cavity wherefrom the water flows out because of gravity.
However, the efficiency of the mudguards made in accordance with this design depends also on the manner by which the water is evacuated from the cavity: therefore it follows that in the upper zone of the wheel housing where the inclination of the surfaces is small, there may be an accumulation or in any case poor drainage of the water, which limits the spray reducing effect of the entire system.
It is perhaps for this reason that such a solution seems to be adopted preferably in the rear zone of the known mudguards, which is rather inclined in the vertical direction.
In the other type of mudguards mentioned above, the water droplets are evacuated by making use of an air flow inside the wheel housing.
In particular, in the second international patent application indicated before there is disclosed a complex system for sucking the air and the water spray from such housing, based on the Venturi effect produced by special channels present in the vehicle or by fans.
It can be understood that such a solution requires modifications to the vehicle (and not only to the mudguard), thereby resulting difficult to be carried out on an industrial level and also expensive.
The present invention aims at overcoming the foregoing state of the art: namely, it has the object of providing a mudguard which reduces the water spray or the dust raised by motor-vehicle wheels, with such structural and operating features as to overcome the limitations of known mudguards.
This object is achieved by a hydro-expeller mudguard, whose characterising features are set out in the claims which will follow.